Several simple suggestions will speed and improve your conversions. We are just trying to make them run as well as possible with the least amount of work, not make the job fancy or complicated.
Trick #1Choosing a Motor. The first decision is choosing which motor. Always choose the biggest and longest motor that will fit. The only "maybe" to that is that "maybe" a shorter motor AND flywheel might work better than the longer motor. In 4-6-2s and 2-8-2s I usually use a Glide Drive B-19 or B-22.
I believe the RM-1624 - 1630 motors run smoother, slower and quieter than the FM-1420 - 1430 motors and "if possible" should be used even if a little extra opening up of the firebox is necessary. This decision is always a trade-off and must be decided upon on an individual basis. The Faulhaber 1524T9.9K bell armature motor is enough shorter than the FM-1430 and RM-1630 to allow the addition of a flywheel in about the same space and its slow speed and smoother, quieter, slower performance I think justifies the extra expence. Experience will make these decisions much easier.
Trick #2. Shortening FM-18 Motors . The plastic end caps of the FM-1824 and FM-1833 are solid plastic and can be ground off all the way up to the metal case except where they hold the bronze shaft bearing and brushes. This allows you to grind the end cap down to the shell leaving only the plastic in a vertical strip about 6mm. wide from brush terminal to bearing to brush terminal and allows this strip to be positioned forward in the driveshaft slot in the bottom of the boiler. This can really help giving you the forward position that leaves enough room for a flywheel on the back of the motor (there is nothing that says the brushes need to be on the back end of the motor - we are talking TRICKS HERE). This is done to all Glide Drive A and B kits except the A-25
Trick #3 Mounting the Motor . A motor mounting bracket is unnecessary, Just make room for the motor and use silicone aquarium sealer (or auto sealer or bathtub sealer) and glue the motor in place. Since this takes 24 hours to harden the ends of the motor must be supported as it sets up ( this is especially true if there is a heavy flywheel on one end). Check the setting after an hour to make sure things have not shifted. If the firebox is hollow or the frame is narrow a brass plate may need to be soldered to the frame to provide the support for the silicone pad to adhere to. If the silicone adheres to the flywheel, cut the silicone with an X-Acto and clean the silicone off the flywheel. It the motor sets up askew, cut it with an Xacto and add some new silicone into the slice, there is no need to remove the old silicone. The silicone allows adjustment of the motor for best alignment of the motor to the gearbox and will dampen minor vibration from an imperfect flywheel.
Trick #4 Universal Joints . A lot of noise is produced by ball and socket universals (especially Samhongsa's machined brass ones). To connect the motor shaft to the worm shaft use silicone surgical tubing (such as ST-15 or ST-20) to replace the old rubber tubing (which was too stiff and became hard or soft with age). If the 2 shafts do not meet insert an intermediate shaft of K&S brass tubing #126 to keep the silicone tubing from flailing around. To add a sliding spline and double universals (such as to the front unit of an articulated) cut a piece of K&S 3/32" square tubing #150 just shorter than needed then cut in half. Insert the next size smaller square tubing #149 inside and you now have a telescoping drive shaft with the silicone tubing making a universal joint to the the input shaft on each end. Try to keep all shafts aligned. If you want it all pre-made we sell this as our UDS drive shaft kits.
Trick #5 Driver Quartering. In many cases a good conversion requires changing the axle gear included in a new gearbox. DON'T PANIC. Using a NWSL 65-4, 55-4 or 45-4 wheel puller makes pulling one wheel and the old gear off the axle easy. Reassemble the new gear, axle bearing and wheel back on the axle making sure you start them square on the axle then use the puller to press the axle back into the gear and wheel. You may need to use a little shim to make sure the counterweight and crankpin boss don't force the wheel off of perpendicular to the axle. QUARTERING; this is what scares people but is not really that difficult. With the wheel reassembled and approximately quartered reinstall it in the frame paying attention to the insulated side (always on Firemans side). Put the siderods on the side that was not pulled (I usually pull the insulated side) and put the rods at noon (vertical) and look at all the crankpin holes on the opposite side. Take small nosed pliers and stick them into the spokes on each side of the wheel to be adjusted and twist as necessary (little pressure required). Examine the wheels again, are all the crank pin holes at about the same place at 3 or 9 Oclock. Rotate the wheels 180 degrees so the siderods are at 6 PM on the back side and compare pin position again and keep comparing and adjusting until every wheel matches. If the rods are at noon and the opposite hole of one wheel is ahead and when the rods are at 6PM the hole is behind, the opposite siderod is not the same length as the axle spacing. Surprisingly quartering is not that critical, rod length is far more critical and is frequently the cause of surging operation. Solder a piece of brass rod in one siderod hole and redrill the hole at the correct length
Trick #6 Tender Pickup. Electrical pickup from the tender is critical and the most problematic. The spring wire on the drawbar guarantees contact to the tender pin but the soulder joint can weaken, if the wire doesn't spring back, resolder it. The top of the tender truck bolsters must be clean where it touches the underfloor and the floor bolster must also be clean. I also clean the bottom of the bolster where the truck spring rests to provide a good second path for electric flow.
The more tender wheels that touch the rail, the more consistant the power to the motor will be. The heavy spring loading of the tender trucks can keep the trucks from rocking fore and aft (lifting a wheel) on undulating track. I file the front and back of the bolster down slightly so only a narrow ridge from side to side contacts the floor and the truck rocks back and forth on rough track to maintain all wheel contact.
The spring can also cause one side of the more lightly loaded truck to lift on rough track. I guess which truck is more lightly loaded and file the sides of the body bolster with slight slopes so the truck will rock easily from side to side. Now all wheels will stay in contact with the rails.
Some more recent locomotives have been built with one or both sideframes equilized to maintain all wheel contact. This requires extra flexibility in both directions with one sideframe flexing and extra flex of one truck from side to side if both sideframes flex. These flex points also can be a source of poor electrical contact from the wheels to the tender because of lacquer or paint. Paint can also get in the axle holes in the sideframes.
Anything we can do to make the conversions simpler makes you more likely to do more. These conversions are surprisingly easy and quick.
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